U.S. patent application number 13/670627 was filed with the patent office on 2013-05-23 for unit and image forming apparatus.
This patent application is currently assigned to Canon Kabushiki Kaisha. The applicant listed for this patent is Canon Kabushiki Kaisha. Invention is credited to Akira Suzuki, Akiko Taira, Toshiteru Yamasaki.
Application Number | 20130129375 13/670627 |
Document ID | / |
Family ID | 47291193 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130129375 |
Kind Code |
A1 |
Yamasaki; Toshiteru ; et
al. |
May 23, 2013 |
UNIT AND IMAGE FORMING APPARATUS
Abstract
A unit for use with an image forming apparatus, includes: a
developer accommodating portion, constituted by a frame, for
accommodating a developer; a sheet member, provided on the frame in
contact with a rotatable member, for preventing the developer from
leaking out from a gap between the developer accommodating portion
and the rotatable member; and a resin member for fixing the sheet
member on the frame, wherein the resin member is formed on the
frame by injection molding of a resin material and is fixed to the
sheet member by welding.
Inventors: |
Yamasaki; Toshiteru;
(Yokohama-shi, JP) ; Suzuki; Akira; (Naka-gun,
JP) ; Taira; Akiko; (Yokohama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Canon Kabushiki Kaisha; |
Tokyo |
|
JP |
|
|
Assignee: |
Canon Kabushiki Kaisha
Tokyo
JP
|
Family ID: |
47291193 |
Appl. No.: |
13/670627 |
Filed: |
November 7, 2012 |
Current U.S.
Class: |
399/103 |
Current CPC
Class: |
G03G 21/1619 20130101;
G03G 21/1832 20130101; G03G 2215/0877 20130101; G03G 21/0029
20130101; G03G 15/0898 20130101 |
Class at
Publication: |
399/103 |
International
Class: |
G03G 15/08 20060101
G03G015/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2011 |
JP |
2011-245731 |
Dec 16, 2011 |
JP |
2011-275772 |
Dec 16, 2011 |
JP |
2011-275773 |
Claims
1. A unit for use with an image forming apparatus, comprising: a
developer accommodating portion, constituted by a frame, for
accommodating a developer; a sheet member, provided on the frame in
contact with a rotatable member, for preventing the developer from
leaking out from a gap between said developer accommodating portion
and the rotatable member; and a resin member for fixing said sheet
member on the frame, wherein said resin member is formed on the
frame by injection molding of a resin material and is fixed to said
sheet member by welding.
2. A unit according to claim 1, wherein said resin member is formed
of the resin material, different from a resin material for the
frame, having an elastic modulus smaller than the resin main
assembly for the frame.
3. A unit according to claim 1, wherein said resin member has an
elastic modulus smaller than that of said sheet member.
4. A unit according to claim 1, wherein said sheet member is welded
on said resin member by heating.
5. A unit according to claim 1, wherein said resin member contains
carbon black for absorbing near infrared ray, wherein said sheet
member is formed of a material capable of transmitting the near
infrared ray, and wherein said sheet member is welded on said resin
member by heat generation of said resin member through absorption
of the near infrared ray.
6. A unit according to claim 1, wherein the frame includes a
regulating portion for regulating, when said resin member is
compressed to weld said sheet member thereon, a position of said
sheet member with respect to a direction perpendicular to a contact
surface where said sheet member and said resin member contact, and
wherein the regulating portion is spaced from said sheet member
after said sheet member is welded on said resin member.
7. A unit according to claim 1, wherein said resin member is formed
at a recessed portion, provided on the frame, by the injection
molding.
8. A unit according to claim 1, wherein said resin member is
non-contact with the frame at a position other than a position
where said resin member contacts the frame when said resin member
is formed on the frame by the injection molding.
9. A unit according to claim 1, wherein said sheet member is welded
on said resin member at one widthwise end portion and contacts the
rotatable member at another widthwise end portion, and wherein the
frame includes a regulating portion contacting a position between
the one and another widthwise end portions of said sheet member so
that said sheet member contacts the rotatable member at the one
widthwise end portion.
10. A unit according to claim 9, wherein the regulating portion
contacts said sheet member welded, at the one widthwise end
portion, on an arcuate end portion of said resin member.
11. A unit according to claim 1, wherein said sheet member is
welded on said resin member along a longitudinal direction of said
resin member, and wherein said resin member has a cross-sectional
shape, with respect to a direction crossing the longitudinal
direction, which is increased from a side where the resin member
contacts said sheet member toward a side where said resin member is
fixed on the frame.
12. A unit according to claim 11, wherein said resin member has a
trapezoidal shape.
13. A unit according to claim 1, wherein the rotatable member is an
image bearing member, and wherein said developer accommodating
portion accommodates the developer removed from the image bearing
member.
14. A unit according to claim 1, wherein the rotatable member is a
developer carrying member for developing an electrostatic latent
image formed on an image bearing member, and wherein said developer
accommodating portion accommodates the developer used on the
developer carrying member.
15. A unit according to claim 1, which is detachably mountable to
the image forming apparatus.
16. An image forming apparatus for forming an image on a recording
material, comprising: a developer accommodating portion,
constituted by a frame, for accommodating a developer; a sheet
member, provided on the frame in contact with a rotatable member,
for preventing the developer from leaking out from a gap between
said developer accommodating portion and the rotatable member; and
a resin member for fixing said sheet member on the frame, wherein
said resin member is formed on the frame by injection molding of a
resin material and is fixed to said sheet member by welding.
Description
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a unit and an image forming
apparatus.
[0002] In the image forming apparatus for forming an image on a
recording material by using an electrophotographic image forming
process, a constitution including a process cartridge detachably
mountable to a main assembly of the image forming apparatus has
been known. The process cartridge is prepared by integrally
assembling an electrophotographic photosensitive member and a
process means acting on the electrophotographic photosensitive
member into a unit, and the process means includes at least one of
a charging means, a developing means and a cleaning means.
According to the process cartridge of this type, maintenance of the
image forming apparatus can be performed by a user himself
(herself) without relying on a service person, so that operativity
can be remarkably improved. Therefore, the process cartridge system
has been widely used in the electrophotographic image forming
apparatus. Examples of the electrophotographic image forming
apparatus may include an electrophotographic copying machine, an
electrophotographic printer (laser beam printer, LED printer or the
like), a facsimile machine and the like.
[0003] A conventional process cartridge will be described with
reference to FIGS. 25 to 28. FIG. 25 is a schematic sectional view
of the conventional process cartridge. FIG. 26 is a schematic view
when an initial tension is applied to a receptor sheet 203. FIG. 27
is a schematic view showing a state change for illustrating
deviation of each of interfaces among a cleaning container 201, a
double-side tape 204 and the receptor sheet 203 when an environment
is changed in the order of normal temperature (e.g., 23.degree.
C.), high temperature (e.g., 50.degree. C.) and normal temperature
(e.g., 23.degree. C.). FIG. 28 is a schematic view for illustrating
a state in which an edge of the receptor sheet 203 mounted on the
cleaning container 201 is waved (undulated).
[0004] Generally, in the electrophotographic image forming
apparatus, the following steps are repeated during image formation.
First, an electrostatic latent image is formed on an
electrophotographic image bearing member (image bearing member 202)
having a photosensitive layer at an outer peripheral surface. The
electrostatic latent image is developed (visualized) as an image
with a developer fed from the developing means via a developer
carrying member 302, and then the resultant image is transferred
onto a transfer material (developer image receiving material).
Further, after an image forming process is ended, the developer and
other deposited matters which remain on the surface of the image
bearing member are sufficiently removed by the cleaning means
before start of a subsequent image forming process.
[0005] As an example of the cleaning means, there is a means
constituted by a cleaning blade 205, the receptor sheet 203 and the
cleaning container 201. The cleaning blade 205 is used for scraping
off a toner remaining on the image bearing member 202, and the
receptor sheet 203 is used for scooping (receiving) the scraped
toner. These members 205 and 203 are provided in contact with the
surface of the image bearing member 202. The cleaning container 201
is provided with a residual toner chamber 200 for storing the
scooped residual toner. The receptor sheet 203 is formed of
biaxially-oriented polyester and is applied onto the cleaning
container 201 at a predetermined position (mounting surface) with
the double-side tape 204. The receptor sheet 203 contacting the
image bearing member 202 is required to be applied onto the
cleaning container 201 with high accuracy without causing the
waving or the like at its edge portion. This is because, in the
case where the receptor sheet 203 is not applied with high
accuracy, the edge of the receptor sheet 203 cannot completely
contact intimately the surface of the image bearing member 202 and
as a result, the developer scraped off by the cleaning blade 205
cannot be scooped with reliability (Japanese Patent No. 3231848).
Further, in order to prevent the waving of the receptor sheet 203
at the edge portion, a tension is applied to the edge of the
receptor sheet 203, so that the receptor sheet 203 is applied onto
the cleaning container 201 so as to obtain an amount of curvature
(initial tension amount) m (FIG. 26). Incidentally, image bearing
member end portion seal members 206a and 206b and a charging roller
207 are provided. Further, in the case where the double-side tape
204 is applied so as to protrude toward the image bearing member
202, the receptor sheet 203 is applied along the double-side tape
204 as shown in FIG. 39. When the receptor sheet 203 is applied in
such a manner, an edge 203a of the receptor sheet 203 cannot
completely contact intimately the surface of the image bearing
member 202 and as a result, the receptor sheet cannot reliably
scoop the developer scraped off by the cleaning blade 205. In order
to prevent such an incomplete application state, a width o1 of a
mounting surface 201a of the cleaning container 201 is sufficiently
ensured so that the double-side tape 204 protrudes toward the image
bearing member 202 (Japanese Patent No. 3231848).
[0006] Further, as an example of the developing means, there is a
means including a developing blade unit 305 and a blowoff
preventing sheet 303. The developing blade unit 305 is used for
regulate a thickness of a layer of the developer carried on the
developer carrying member 302 in an upstream side with respect to a
rotational direction of the developer carrying member 302. The
blowoff preventing sheet is used for preventing the blowoff
(leakage) of the developer from inside to outside of the developing
container 301. These developing blade unit 305 and blowoff
preventing sheet 303 are provided in contact with the surface of
the developer carrying member 302. Further, the blowoff preventing
sheet 303 is formed of biaxially-oriented polyester and is applied
onto the developing container 301 at a predetermined position
(mounting surface) with a double-side tape 304. Also with respect
to the blowoff preventing sheet 303, similarly as in the case of
the receptor sheet 203 described above, there is a need to apply
the blowoff preventing sheet 303 onto the developing container 301
with high reliability without causing the waving or the like at an
edge portion. This is because, in the case where the blowoff
preventing sheet 303 is not applied with high accuracy, the edge of
the blowoff preventing sheet 303 cannot completely contact
intimately the surface of the developer carrying member 302 and as
a result, the developer in the developing container 301 is blown
off from a gap therebetween. Further, similarly as in the case of
the receptor sheet 203, in order to prevent the waving of the
blowoff preventing sheet 303 at the edge portion, a tension is
applied to the edge of the blowoff preventing sheet 303, so that
the blowoff preventing sheet 303 is applied onto the developing
container 301 so as to obtain an amount of curvature (initial
tension amount). Incidentally, developer carrying member end
portion seal members 306a and 306b are provided.
[0007] As described above, the receptor sheet 203 and the blowoff
preventing sheet 303 (hereinafter, these sheets are referred to as
a thin plate member) are applied onto the cleaning container 201 or
the developing container 301 (hereinafter, these containers are
referenced to as a frame) by using the double-side tapes. Further,
their application positions are important since they largely affect
developer leakage prevention from the frames. For this reason,
there is a need to apply the double-side tape onto the frame with
high accuracy in order to prevent the leakage of the developer, and
the prevention of the waving of the thin plate member edge is
important. The thin plate member is required to prevent the waving
of the thin plate member edge with respect to a change in
temperature (e.g., 0.degree. C. to 50.degree. C.) at a periphery of
an associated cartridge in the image forming apparatus during rest
(stop) and operation of the image forming apparatus.
[0008] For example, as shown in FIG. 27, in the case where the
cartridge is left standing in the environment in the order of
normal temperature (e.g., 23.degree. C.), high temperature (e.g.,
50.degree. C.) and NT (e.g., 23.degree. C.), each of the members is
elongated corresponding to its linear expansion coefficient. In
this case, the double-side tape 204 deviates (shifts) at an
interface thereof with each of the cleaning container 201 and the
receptor sheet 203, thus absorbing a difference in elongation
between the cleaning container 201 and the receptor sheet 203.
Further, in some cases, the deviation cannot be restored to an
original state when the temperature is returned to the normal
temperature and remains as y1 and y2. At this time, in the case
where the amount of curvature (initial tension amount) m is
insufficient, the curvature amount m becomes small, so that waving
W as shown in FIG. 28 is generated in some cases.
[0009] In recent years, in a cartridge assembling step by an
automatic machine, in order to further reduce a cost, improvements
in manufacturing efficiency and product manufacturing accuracy are
required. Further, with improvements in performance and image
quality of the electrophotographic image forming apparatus,
downsizing of the cartridge is required. However, in the
above-described bonding (application) method in which the thin
plate member is applied onto the frame with the double-side tape,
the following problems arose. The double-side tape is soft and
therefore when a width of the double-side tape is made small for
the purposes of the cost reduction and the downsizing of the
cartridge, meandering of the double-side tape is generated and thus
it is difficult to apply the thin plate member onto the cartridge
frame with high accuracy. Further, after the cartridge is left
standing in the high temperature environment, the deviation is
generated at the interface between the double-side tape and the
thin plate member and at the interface between the double-side tape
and the cartridge frame and thus the curvature amount m is
decreased, so that the initial tension of the thin plate member is
attenuated. For that reason, there was a need to control the
tension amount of the thin plate member edge in consideration of
the initial tension attenuation.
SUMMARY OF THE INVENTION
[0010] A principal object of the present invention is to provide a
unit and an image forming apparatus which are capable of mounting a
sheet member on a frame with high accuracy.
[0011] According to an aspect of the present invention, there is
provided a unit for use with an image forming apparatus,
comprising: a developer accommodating portion, constituted by a
frame, for accommodating a developer; a sheet member, provided on
the frame in contact with a rotatable member, for preventing the
developer from leaking out from between the developer accommodating
portion and the rotatable member; and a resin member for fixing the
sheet member on the frame, wherein the resin member is formed on
the frame by injection molding of a resin material and is fixed to
the sheet member by welding.
[0012] These and other objects, features and advantages of the
present invention will become more apparent upon a consideration of
the following description of the preferred embodiments of the
present invention taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic sectional view showing a general
structure of an image forming apparatus in Embodiment 1.
[0014] FIG. 2 is a schematic sectional view showing a process
cartridge in Embodiment 1.
[0015] FIG. 3 is a schematic sectional view showing a cleaning
member and an image bearing member in Embodiment 1.
[0016] FIG. 4 is a schematic sectional view showing a structure of
the cleaning member in Embodiment 1.
[0017] FIG. 5 is a structural illustration of the cleaning member
in Embodiment 1 as seen from an arrow a direction shown in FIG.
4.
[0018] FIGS. 6 and 7 are schematic sectional views each showing
constituent members of a developing unit in Embodiment 1.
[0019] FIG. 8 is an illustration of the developing unit in
Embodiment 1 as seen from an arrow a direction shown in FIG. 7.
[0020] Parts (a) to (d) of FIG. 9 are schematic views for
illustrating molding of an elastomer member in Embodiment 1.
[0021] FIG. 10 is a schematic sectional view for illustrating the
molding of the elastomer member in Embodiment 1 taken along A-A
line indicated in (b) of FIG. 9.
[0022] FIG. 11 is a schematic view showing a state of the elastomer
member during molding in Embodiment 1.
[0023] Parts (a) and (b) of each of FIGS. 12 to 17 are structural
illustrations showing a molded shape of the elastomer member in
Embodiment 1.
[0024] Parts (a) and (b) of FIG. 18 are illustrations of a cleaning
container on which a receptor sheet is mounted in Embodiment 1.
[0025] Parts (a) and (b) of FIG. 19 are schematic views for
illustrating a method of applying tension to an upper edge of the
receptor sheet in Embodiment 1.
[0026] FIG. 20 is an illustration showing a state in which the
elastomer member is melted to weld a sheet in Embodiment 1.
[0027] FIG. 21 is a schematic sectional view showing the state in
which the elastomer member is melted to weld the sheet in
Embodiment 1.
[0028] FIG. 22 is an enlarged view of D portion, indicated in FIG.
21, showing the state in which the elastomer member is melted to
weld the sheet in Embodiment 1.
[0029] FIG. 23 is an illustration showing the cleaning container on
which the receptor sheet is welded in Embodiment 1.
[0030] Parts (a) and (b) of FIG. 24 are schematic views showing a
molded shape of the elastomer member in Embodiment 1.
[0031] FIG. 25 is a schematic sectional view of a conventional
process cartridge.
[0032] FIG. 26 is a schematic view showing a cleaning container and
a receptor sheet when initial tension is applied to the receptor
sheet.
[0033] FIG. 27 is a schematic view showing a change in state of
interfacial deviation in environments of normal temperature and
high temperature.
[0034] FIG. 28 is an illustration showing a waving state of an
upper edge of the receptor sheet.
[0035] Parts (a) and (b) of FIG. 29 are schematic sectional views
showing a cleaning container on which a receptor sheet is mounted
in Embodiment 2.
[0036] Parts (a) and (b) of FIG. 30 are schematic views for
illustrating a method of applying tension to the sheet with a
tension tool in Embodiment 2.
[0037] FIG. 31 is an illustration of sheet welding.
[0038] FIG. 32 is a schematic sectional view for illustrating the
sheet welding.
[0039] FIG. 33 is an enlarged view of D portion indicated in FIG.
32 in Embodiment 2.
[0040] FIG. 34 is an illustration showing the cleaning container on
which the receptor sheet is welded in Embodiment 2.
[0041] FIG. 35 is a schematic sectional view showing a state in
which the receptor sheet is welded in Embodiment 2.
[0042] FIG. 36 is a schematic sectional view showing a state in
which the receptor sheet is contacted to a sheet-regulating surface
in Embodiment 2.
[0043] Parts (a), (b), (a-1) and (b-1) of FIG. 37 are schematic
views for illustrating an effect of a molded shape of an elastomer
member in Embodiment 3.
[0044] Parts (a) to (d) of FIG. 38 are schematic views each for
illustrating an effect of a molded shape of an elastomer member in
Embodiment 3.
[0045] FIG. 39 is an illustration showing a state in which a sheet
is inclined to generate a gap between the sheet and a developer
carrying member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
[0046] Hereinbelow, embodiments for carrying out the present
invention will be exemplarily and specifically described based on
Embodiment 1 with reference to the drawings. However, dimensions,
materials, shapes, relative arrangements and the like of
constituent elements described in the following embodiments are
appropriately changed depending on constitutions or various
conditions of devices (apparatuses) to which the present invention
is applied. That is, the scope of the present invention is not
limited thereto.
[0047] In the following description, a longitudinal direction of a
process cartridge is a direction (rotational axis direction of an
image bearing member) crossing (substantially perpendicular to) a
direction in which the process cartridge is mounted into an
electrophotographic image forming apparatus main assembly. Left and
right of the process cartridge are those as seen from the direction
in which the process cartridge is mounted into the
electrophotographic image forming apparatus main assembly.
[0048] An upper surface of the process cartridge is a surface
located at an upper portion of the process cartridge in a state in
which the process cartridge is mounted in the electrophotographic
image forming apparatus main assembly, and a lower surface is a
surface located at a lower portion of the process cartridge in the
mounted state.
(Structure of Image Forming Apparatus Main Assembly)
[0049] A structure of a main assembly of the electrophotographic
image forming apparatus in Embodiment 1 according to the present
invention will be described with reference to FIG. 1. FIG. 1 is a
schematic sectional view of a color laser beam printer as an
example of the image forming apparatus (hereinafter referred to as
an image forming apparatus main assembly). An image forming
apparatus main assembly 100 includes process cartridges 2 for
colors of Y (yellow), M (magenta), C (cyan) and Bk (black), an
intermediary transfer belt (intermediary transfer member) 35, a
fixing portion 50, a group of discharging rollers 53, 54 and 55,
and a discharge tray 56. The process cartridges 2 for the four
colors are independently constituted so as to be detachably
mountable to the image forming apparatus main assembly 100.
[0050] Next, an operation of the image forming apparatus main
assembly 100 will be described. First, a sheet feeding roller 41 is
rotated to separate a sheet of a transfer material (recording
material) P in a sheet feeding cassette 7 and then feeds the
transfer material P to a registration roller 44. On the other hand,
an image bearing members 21 and the intermediary transfer member 35
are rotated in an arrow direction in FIG. 1 at a predetermined
outer peripheral speed V (hereinafter referred to as a process
speed). A surface of the image bearing member 21 is electrically
charged uniformly by the charging means and is subjected to
exposure to light by a laser, so that an electrostatic latent image
is formed. Simultaneously with this latent image formation, a
developing unit 2b develops the latent image on the image bearing
member 21 with a developer (toner). The color images of Y, M, C and
Bk formed on the image bearing member 21 by development are
primary-transferred onto an outer peripheral surface of the
intermediary transfer member 35. The respective color images
transferred onto the intermediary transfer member 35 are
secondary-transferred onto the transfer material P and thereafter
are fixed on the transfer material P. The transfer material P on
which the images are fixed is discharged onto the discharge tray 56
via the discharge roller pairs 53, 54 and 55, so that the image
forming operation is ended.
(Structure of Process Cartridge)
[0051] With reference to FIG. 2, a structure of the process
cartridge 2 in this embodiment will be described. FIG. 2 is a
schematic sectional view of the process cartridge 2. The process
cartridges for Y, M, C and Bk have the same constitution. The
process cartridge 2 is divided into a cleaning unit 2a and a
developing unit 2b.
[0052] In the cleaning unit 2a, the image bearing member 21 as a
rotatable member is rotatably mounted to a cleaning container 24.
On a peripheral surface of the image bearing member 21, a charging
roller 23 as a primary charging means for uniformly charging the
surface of the image bearing member 21 and a cleaning blade 28 for
removing the toner remaining on the image bearing member 21 are
provided. Further, a receptor sheet (thin plate member) 15 as a
flexible sheet member for scooping the toner removed by the
cleaning blade 28 and an elastomer member (adhesive member) 10 as a
resin member on which the receptor sheet 15 is fixed are provided.
Further, a charging roller cleaner 17 for cleaning the charging
roller 23 and an elastomer member 12 for fixing the charging roller
cleaner 17 are provided.
[0053] The developing unit 25 is constituted by a developer
carrying member 22 as a developing means, a toner container
(developer accommodating portion) 70 accommodating the toner, and a
developing container 71. The developer carrying member 22 is
rotatably supported by the developing container 71. On a peripheral
surface of the developer carrying member 22, a toner supplying
roller 72 rotating an arrow Z direction in contact with the
developer carrying member 22, a developer regulating member 73, a
blowoff preventing sheet (thin plate member) 16, and an elastomer
member (adhesive member) for fixing the blowoff preventing sheet 16
are provided. Further, in the toner container 70, a toner stirring
mechanism 74 is provided.
[0054] Next, an operation of the process cartridge 2 will be
described. First, the toner is fed to the toner supplying roller 72
by the toner stirring mechanism 74 rotating in an arrow X direction
in FIG. 2. The toner supplying roller 72 supplies the toner to the
developer carrying member 22 by rotating in the arrow z direction.
The toner supplied onto the developer carrying member 22 reaches a
position of the developer regulating member (developing blade unit)
73 by rotation of the developer carrying member 22 in an arrow Y
direction. The developer regulating member 73 regulates the toner
to impart a desired electric charge amount to the toner and to form
a predetermined thin toner layer. The toner regulated by the
developer regulating member 73 is fed to a developing portion where
the image bearing member 21 and the developer carrying member 22
contact and is used for development on the image bearing member
under application of a developing bias to the developer carrying
member 22. The toner used for development on the image bearing
member 21 is primary-transferred onto the intermediary transfer
member 35 and thereafter a residual toner remaining on the image
bearing member 21 is removed by a cleaning blade 28. The removed
residual toner is stored in a residual toner chamber (developer
accommodating portion) 30.
(Cleaning Unit)
[0055] With reference to FIGS. 3 to 5, a structure of the cleaning
unit 2a will be described. FIG. 3 is a schematic sectional view
showing the cleaning member and the image bearing member 21, FIG. 4
is a schematic sectional view showing a structure of the cleaning
member, and FIG. 5 is an illustration of the cleaning means as seen
from an arrow a direction in FIG. 4.
[0056] As shown in FIGS. 3 and 4, the cleaning blade 28 for
scraping off a residual matter such as the residual toner from the
image bearing member 21, and the receptor sheet 15 for scooping the
scraped residual toner are provided. Further, the residual toner
chamber 30 for accommodating the residual matter, image bearing
member end portion seal members 26a and 26b, provided at end
portions of the cleaning blade 28 so as to prevent the residual
matter from leaking out of the residual toner chamber 30, and an
under-cleaning blade seal 27 are provided. These members are
incorporated into an assembled with the cleaning container 24 to
constitute the cleaning unit 2a.
[0057] Specifically, as shown in FIG. 5, the cleaning blade 28 and
the receptor sheet 15 contact the outer peripheral surface of the
image bearing member 21 at a position where they do not interfere
with each other and where an opening 24a is formed. The receptor
sheet 15 is welded on an elastomer member 10 portion formed by
injection molding, as the adhesive member for the receptor sheet
15, on the cleaning container 24. This will be described later
specifically. The image bearing member 21 is configured such that
it is disposed at the opening 24a of the cleaning container 24, and
the receptor sheet 15 is provided for preventing the toner from
leaking out from a gap between the cleaning container 24 and the
image bearing member 21 by the contact with the image bearing
member 21. Further, the image bearing member end portion seal
members 26a and 26b are disposed on the basis of the cleaning blade
28 as shown in FIG. 5 and are contacted to the receptor sheet 15 at
end portions, and are also contacted to the outer peripheral
surface of the image bearing member 21 as shown in FIG. 3. Further,
by the under-cleaning blade seal 27, a gap between the cleaning
blade 28 and the cleaning container 24 or the like gap is
hermetically sealed.
[0058] Further, a charging roller cleaner 17 for cleaning the
charging roller 23 is provided and welded on an elastomer member 12
portion molded, as an adhesive member for the charging roller
cleaner 17, on the cleaning container 24.
(Developing Unit)
[0059] With reference to FIGS. 6 to 8, a structure of the
developing unit 2b will be described. FIG. 6 is a schematic
sectional view showing the blowoff preventing sheet 16, the
developing blade unit 73, developer carrying member end portion
seal members 95a and 95b, and the developer carrying member 22.
FIG. 7 is a schematic sectional view showing the blowoff preventing
sheet 16, the developing blade unit 73, and the developer carrying
member end portion seal members 95a and 95b. FIG. 8 is a schematic
view of the these members as seen from an arrow a direction shown
in FIG. 7.
[0060] As shown in FIGS. 6 and 7, the developing blade unit 73 for
uniformizing the toner on the developer carrying member 22 and the
blowoff preventing sheet 16 for preventing the toner from blowing
off from a gap between the developer carrying member 22 and the
developing container 71 are provided. Further, the developing
container 71 for accommodating the toner, the developer carrying
member end portion seal members 95a and 95b provided at end
portions of the developing blade unit 73 so as to prevent the
residual matter from leaking out of the process cartridge 71, and
an under-developing blade seal 93 are provided. These members are
incorporated into an assembled with the developing container 71 to
constitute the developing unit 2a.
[0061] Specifically, as shown in FIG. 8, the developing blade unit
73 and the blowoff preventing sheet 16 contact the outer peripheral
surface of the developer carrying member 22 at a position where
they do not interfere with each other and where an opening 71a is
formed. The blowoff preventing sheet 16 is welded on an elastomer
member 11 portion molded, as the adhesive member for the blowoff
preventing sheet 16, on the developing container 71. This will be
described later specifically. Further, the developer carrying
member end portion seal members 95a and 95b are, as shown in FIG.
8, contacted to the developing blade unit 73 and the blowoff
preventing sheet 16 at end portions, and are also contacted to the
outer peripheral surface of the developer carrying member 22 as
shown in FIG. 6. Further, by the under-developing blade seal 93, a
gap between the developing blade unit 73 and the developing
container 71 or the like gap is hermetically sealed.
[0062] Further, a scattering preventing sheet 18 for preventing
toner scattering is provided and welded on an elastomer member 13
portion molded, as an adhesive member for the scattering preventing
sheet, on the developing container 71.
(Molding of Elastomer Member)
[0063] With reference to FIGS. 9 to 11, a molding process of the
elastomer member 10 will be described. Parts (a) to (d) of FIG. 9
are schematic views for illustrating molding of the elastomer
member 10 as the adhesive member, wherein (a) of FIG. 9 includes a
schematic view of the cleaning container 24 and a schematic
enlarged view of an injection port portion, (b) of FIG. 9 is a
schematic view showing a state in which an elastomer molding metal
mold 83 is clamped on the cleaning container 24, (c) of FIG. 9 is a
schematic sectional view taken along A-A line indicated in (b) of
FIG. 9, and (d) of FIG. 9 is a schematic sectional view taken along
B-B line indicated in (b) of FIG. 9. FIG. 10 is a schematic
sectional view taken along the A-A line indicated in (b) of FIG. 9
and shows a state of the elastomer member 10 during molding. FIG.
11 is a schematic view showing the state of the elastomer member
during molding.
[0064] As shown in (a) to (d) of FIG. 9, an elastomer
member-forming portion 71d is provided between the image bearing
member end portion seal members 26a and 26b in an end side and
another end side, respectively, of the cleaning container 24. The
elastomer member-forming portion 71d includes a recessed portion
71d1 into which the elastomer member 10 is to be injected, and
contact surfaces 71d2 and 71d3 to which the metal mold is to be
contacted. Further, at a predetermined longitudinal position, a
cylindrical injection port 76 which communicates with the recessed
portion 71d1 of the seal (elastomer member forming portion 71d is
provided.
[0065] Next, a molding method of the elastomer member 10 will be
described. In this embodiment, as shown in (a) of FIG. 9, the
injection port 76 is provided at one longitudinal central portion
of the elastomer member-forming portion 71d but may also be
provided at two positions or more. When the elastomer member 10 is
molded, as shown in (c) and (d) of FIG. 9, the elastomer molding
metal mold 83 is contacted to the contact surfaces 71d2 and 71d3 of
the elastomer member-forming portion 71d of the cleaning container
24. The elastomer molding metal mold 83 is configured to be cut
into a shape of the elastomer member 10, i.e., is provided with a
recessed portion 83d having a shape corresponding to an outer shape
of the elastomer member 10. Then, a gate 82 of a resin material
injection device is contacted to the injection port 76 provided at
the one longitudinal central portion of the cleaning container 24.
Then, a thermoplastic elastomer (resin material) for constituting
the elastomer member 10 is injected from the gate 82 of the resin
material injection device into the injection port 76 of the
cleaning container 24 as indicated by an arrow in (c) of FIG. 9.
The injected thermoplastic elastomer is caused to flow into a
molding space formed, as shown in FIG. 10, by the recessed portion
71d1 of the elastomer member-forming portion 71d of the cleaning
container 24 and the recessed portion 83d of the elastomer molding
metal mold 83. The thermoplastic elastomer injected from the one
longitudinal central portion flows, as shown in FIG. 11, in the
molding space formed by the recessed portion 71d1 of the elastomer
member-forming portion 71d and the recessed portion 83d of the
elastomer molding metal mold 83, toward longitudinal end sides.
Thus, the thermoplastic elastomer is injected and molded in the
molding space formed by bringing the mold into contact with the
cleaning container 24, so that the elastomer member 10 is molded
integrally with the cleaning container 24.
[0066] The elastomer member 10 is integrally molded with the
cleaning container 24. In this embodiment, as the material for the
elastomer member 10, a styrene-based elastomer resin material is
used. This is because the cleaning container 24 is formed of
high-impact polystyrene (HI-PS) and therefore as the elastomer
resin material, the styrene-based elastomer resin material which is
the same type material as HI-PS and has elasticity is preferred.
When parts of the same type resin materials are used, the parts are
not required to be disassembled from each other and therefore the
parts are excellent in disassembling operativity during recycling
of the process cartridge. Incidentally, an elastomer resin toner
other than the above-described elastomer resin material may also be
used so long as it has a similar mechanical characteristic.
[0067] In this embodiment, as the elastomer member 10 to be formed
by the molding, an elastomer member having a physical property of
2.5 MPa to 10 MPa in elastic modulus is used. Adjustment of the
elastic modulus was effected by incorporating 20 wt. parts of
polyethylene (PE) into 100 wt. parts of the styrene-based elastomer
resin material. However, the elastomer resin material may only be
required to provide the resultant elastomer member with the elastic
modulus of 2.5 MPa to 10 MPa, and therefore the content of PE may
be changed and a resin material other than PE may also be used. It
is also possible to use other elastomer resin materials.
[0068] The above-described molding method of the elastomer member
10 with the cleaning container 24 may also be applicable to molding
of the elastomer members 11 and 13 with the developing container 71
and molding of the elastomer member 21 with the cleaning container
24. Incidentally, as the molding method of the elastomer members
10, 11, 12 and 13, in addition to the above-described molding
method, it is also possible to effect the molding on the frame such
as the cleaning container 24, the developing container 71 or the
like by two-color molding, insert molding or the like.
[0069] In the case of a conventional method using a double-side
tape as the adhesive member, the double-side tape is soft and
therefore it is more difficult to apply the double-side tape onto
the frame with a narrower width of the double-side tape. However,
in Embodiment 1, the elastomer resin material is directly molded
into the elastomer member with the frame by using the mold, so that
the elastomer member can be formed on the frame with a higher
degree of accuracy than that of the double-side tape. Further, in
the case of the conventional method using the double-side tape as
the adhesive member, after the resultant structure is left standing
in a high temperature environment, deviation is generated at a
bonded interface between the double-side tape and the frame.
However, in Embodiment 1, the elastomer member is directly formed
on the frame by molding, so that it is possible to suppress
deviation at a bonded interface between the elastomer member and
the frame.
(Molded Shape of Elastomer Member on Container)
[0070] With reference to FIGS. 12 to 17, various structural
examples of molded shapes of the elastomer members 10, 11, 12 and
13 integrally molded with the frame (such as the cleaning container
24 or the developing container 71) and the elastomer member-forming
portion on the frame will be described.
[0071] Parts (a) and (b) of FIG. 12 are schematic views for
illustrating a molded shape 1 of the elastomer member 10, in which
(a) of FIG. 12 is a schematic front view showing the elastomer
member 10 and a part of the frame, and (b) of FIG. 12 is a
schematic sectional view taken along a line indicated by arrows in
(a) of FIG. 12. Parts (a) and (b) of FIG. 13 are schematic views
for illustrating a molded shape 2 of the elastomer member 10, in
which (a) of FIG. 13 is a schematic front view showing the
elastomer member 10 and a part of the frame, and (b) of FIG. 13 is
a schematic sectional view taken along a line indicated by arrows
in (a) of FIG. 13. Parts (a) and (b) of FIG. 14 are schematic views
for illustrating a molded shape 4 of the elastomer member 10, in
which (a) of FIG. 14 is a schematic front view showing the
elastomer member 10 and a part of the frame, and (b) of FIG. 14 is
a schematic sectional view taken along a line indicated by arrows
in (a) of FIG. 14. Parts (a) and (b) of FIG. 15 are schematic views
for illustrating a molded shape 2 of the elastomer member 10, in
which (a) of FIG. 15 is a schematic front view showing the
elastomer member 10 and a part of the frame, and (b) of FIG. 15 is
a schematic sectional view taken along a line indicated by arrows
in (a) of FIG. 15. Parts (a) and (b) of FIG. 16 are schematic views
for illustrating a molded shape 5 of the elastomer member 10, in
which (a) of FIG. 16 is a schematic front view showing the
elastomer member 10 and a part of the frame, and (b) of FIG. 16 is
a schematic sectional view taken along a line indicated by arrows
in (a) of FIG. 16. Parts (a) and (b) of FIG. 17 are schematic views
for illustrating a molded shape 6 of the elastomer member 10, in
which (a) of FIG. 17 is a schematic front view showing the
elastomer member 10 and a part of the frame, and (b) of FIG. 17 is
a schematic sectional view taken along a line indicated by arrows
in (a) of FIG. 17.
[0072] As show in (a) and (b) of FIG. 12, in the molded shape 1,
the elastomer member 10 formed by molding at the recessed portion
as the elastomer member-forming portion 71d1 of the frame is in
non-contact with the frame with widths o1 and o2, which are larger
than 0 mm, with respect to an entire widthwise region except for
longitudinal end portions. That is, a regulating portion capable of
regulating a position of the sheet member of the frame is provided
with spacings o1 and o2 from the elastomer member 10 with respect
to the widthwise direction of the elastomer member 10.
[0073] Further, as shown in (b) of FIG. 12, the elastomer resin
material is molded while ensuring a free length (height) h of 0.5
mm or more and entering the frame with a depth k of 0.3 mm during
the molding into the elastomer member 10. That is, the elastomer
resin material is injected and molded so that a part of the
elastomer member 10 enters the recessed portion of the frame. This
is because a sheet welding portion of the elastomer member 10 is
prevented from being influenced by elongation due to linear
expansion of the frame under left-standing in the high temperature
environment and also because the elastomer member 10 is fixed on
the frame. Further, a height of a sheet member mounting surface
(contact position) 24 before welding of the elastomer member 10 is
made higher than a height of a contact surface (contact position)
of the frame to be contacted with the sheet member of the sheet
member regulating portion, by an elastomer member melting margin
i.
[0074] The molded shape of the elastomer member 10 in this
embodiment may only be required to possess the following features
(1) to (3).
[0075] (1) The sheet member mounting surface 24d of the elastomer
member 10 is not influenced by the elongation due to linear
expansion of the frame under left-standing in the high temperature
environment.
[0076] (2) The elastomer member 10 functions as a buffer layer
which prevents the sheet member (thin plate member) such as the
receptor sheet 15 from being influenced by the linear expansion of
the frame.
[0077] (3) The elastomer member 10 is not easily detached from the
frame.
[0078] When the above three features (1) to (3) are satisfied, as
shown in (a) and (b) of FIG. 13, a constitution (molded shape 2) in
which the elastomer member 10 is in non-contact with the frame in
entire longitudinal and widthwise regions with widths p1 and p2
which are larger than 0 mm and with widths o1 and o2 which are
larger than 0 mm may also be employed. Further, when the elastomer
member 10 has an adhesive property, as shown in (a) and (b) of FIG.
14, a constitution (molded shape 3) in which the frame is not
provided with the recessed portion but the elastomer member 10 is
formed in a projected shape on the flat surface of the frame may
also be employed. Further, in the case where a sufficiently
flexible elastomer member 10 is formed by molding, as shown in (a)
and (b) of FIG. 15, a constitution (molded shape 4) in which the
free length (height) from the frame is made smaller than that of
the molded shape 1 may also be employed. Further, as shown in (a)
and (b) FIG. 16, a constitution (molded shape 5) in which the depth
of the elastomer member-forming portion 71d1 is made deeper than
that of the molded shape 1 while making the free length from the
frame smaller than that of the molded shape 1 may also be employed.
Further, as shown in (a) and (b) of FIG. 17, a constitution (molded
shape 6) in which the elastomer member 10 is formed by molding so
as to cover a projected portion provided on the frame may also be
employed.
[0079] The above-described various structural examples of the
molded shapes of the elastomer member 10 with the cleaning
container 24 are also applicable to molded shapes of the elastomer
members 11 and 13 with the developing container 71 and molded
shapes of the elastomer member 12 with the cleaning container
24.
[0080] In the case of the conventional method using the double-side
tape as the adhesive member, the double-side tape functions as a
buffer material for absorbing a difference in linear expansion,
under left-standing in the high temperature environment, between
the frame and the sheet member, so that waving of the sheet member
after being left standing in the high temperature environment can
be prevented. Therefore, also in Embodiment 1, by forming the
elastomer member 10 on the frame by molding, the elastomer member
10 can function as the buffer material for absorbing the difference
in linear expansion, under left-standing in the high temperature
environment, between the frame and the sheet member. By this
effect, it becomes possible to prevent waving of the sheet member
after being left standing in the high temperature environment.
(Sheet Welding)
[0081] With reference to FIGS. 18 to 24, a sheet welding step in
this embodiment of the present invention will be described by
taking the case where a semiconductor laser is used, as an
example.
[0082] Parts (a) and (b) of FIG. 18 are schematic illustrations of
the cleaning container on which the receptor sheet 15 is mounted,
in which (a) of FIG. 18 shows a state in which waving of the
receptor sheet 15 is not generated, and (b) of FIG. 18 shows a
state in which waving of the receptor sheet 15 is generated. Parts
(a) and (b) of FIG. 19 are schematic views for illustrating a
method of imparting tension to an upper edge of the receptor sheet,
in which (a) of FIG. 19 shows a state in which the sheet member
mounting surface 24d of the cleaning container 24 is curved by a
tension (pulling) jig 48, and (b) of FIG. 19 shows a state in which
the tension is imparted to the upper edge of the receptor sheet 15
by relieving the curve of the sheet member mounting surface 24d of
the cleaning container 24. FIG. 20 is a schematic view for
illustrating a state in which the elastomer member 10 formed on the
cleaning container 24 by molding is melted to weld the receptor
sheet 15. FIG. 21 is a schematic sectional view showing the state
of FIG. 20. FIG. 22 is a partially enlarged view of portion D shown
in FIG. 21. FIG. 23 is a schematic view for illustrating the
cleaning container 24 on which the receptor sheet 15 is welded on
the elastomer member 10. Parts (a) and (b) of FIG. 24 are schematic
view showing a molded shape of the elastomer member in Embodiment
1, in which (a) of FIG. 24 is a schematic front view of the molded
shape, and (b) of FIG. 24 is a schematic sectional view of the
molded shape.
[0083] In this embodiment, the receptor sheet 15 formed of
polyester with a thickness of 38 .mu.m and a light transmittance of
85% (near infrared ray of 960 nm) was used. First, as shown in (a)
of FIG. 18, the cleaning container 24 is prepared. In this case, as
shown in (b) of FIG. 18, waving x can occur at an edge (contact
portion with the image bearing member 21) of the receptor sheet 15
due to creases of the receptor sheet 15 itself, an environmental
fluctuation, and the like. For this reason, when the receptor sheet
15 is mounted, as shown in (a) of FIG. 19, a force-receiving
portion (for receiving a force when the sheet member mounting
surface 24d is curved) of the sheet member mounting surface 24d of
the cleaning container 24 is pulled downward by the tension jig 48.
By elastic deformation at this time, the sheet member mounting
surface 24d is curved, and the receptor sheet 15 is mounted in this
state and thereafter the curve is released. In this way, by curving
the cleaning container 14, an initial tension amount n is provided
to the edge of the receptor sheet 15 as shown in (b) of FIG. 19, so
that waving is prevented. In this embodiment, the initial tension
amount n is provided in a range of 0.5 mm to 0.8 mm.
[0084] As shown in FIGS. 20 to 22, in this embodiment, in a state
in which a lower portion of the sheet member mounting surface 24d
of the elastomer member 10 formed on the cleaning container 24 by
molding is curved by using the tension jig 48, the receptor sheet
15 is superposed on the sheet member mounting surface 24d so as to
be contacted to the sheet member mounting surface 24d. Further, the
receptor sheet 15 is press-contacted to a sheet position regulating
surface 49 by using an urging jig 45, which is transparent to near
infrared ray, from above the receptor sheet 15. As a result, the
receptor sheet 15 is temporarily positioned so that a position of
the receptor sheet 15 relative to the cleaning container 24 is not
shifted (deviated) during bonding of the receptor sheet 15.
[0085] Thereafter, laser light e of near infrared ray is emitted
from a laser irradiation head 60, via the receptor sheet 15, toward
the sheet member mounting surface 24d of the elastomer member 10
formed on the cleaning container 24 by molding. The elastomer
member 10 contains carbon black so as to absorb near infrared ray.
For this reason, the emitted laser light e passes through the
urging jig 45 and the receptor sheet 15 which are transparent to
near infrared ray, and is absorbed by the sheet member mounting
surface 24d of the elastomer member 10 formed on the cleaning
container 24 by molding. The laser light absorbed by the sheet
member mounting surface 24d is conversed into heat and thus the
sheet member mounting surface 24d generates heat, so that the
elastomer member 10 is melted by the heat and thus can be welded
with (bonded to) the receptor sheet 15 contacting the sheet member
mounting surface 24d.
[0086] Here, the laser light e emitted from the irradiation head 60
was focused to a circular spot of 1.5 mm in diameter when it
reaches the sheet member mounting surface 24d. That is a spot
diameter of the laser light is 1.5 mm. Further, by making a molding
width of the elastomer member smaller than 1.5 mm, it becomes
possible to uniformly melt the sheet member mounting surface 24d of
the elastomer member 10. Therefore, in this embodiment, a melting
width el of the elastomer member 10 is about 1.0 mm. Further, the
receptor sheet 15 is irradiated with the laser light continuously
from its end portion to its another end portion. As a result, a
welded surface g1 continuously extending in the longitudinal
direction as shown in FIG. 23 can be obtained.
[0087] Further, as the urging jig 45, a member having a rigidity
such that it can press an entire contact surface between the
receptor sheet 15 and the sheet member mounting surface 24d of the
elastomer member 10 formed on the cleaning container 24 by molding
may preferably be used. Specifically, acrylic resin, glass and the
like may preferably be used.
[0088] Further, the cleaning container 24 on which the elastomer
member 10 having the sheet member mounting surface 24d is formed by
molding is formed of the resin material, so that when the receptor
sheet 15 is mounted, the sheet member mounting surface 24d is
curved to cause some unevenness or deformation in some cases.
Further, in some cases, the position of the receptor sheet 15
relative to the cleaning container 24 is shifted. Therefore, in
this embodiment, the urging jig 45 was provided with an elastic
urging member 47. By the urging member 47, the receptor sheet 15 is
elastically urged toward the cleaning container 24 to be
temporarily positioned, so that an adhesive property between the
receptor sheet 15 and the sheet member mounting surface 24d can be
improved. Further, positional deviation of the receptor sheet 15
can be prevented. Specifically, as the urging jig 45, a member
including an acrylic member 46 as a rigid member and a 5 mm-thick
silicone rubber member (urging member) 47 as an elastic member
which are bonded with a transparent double-side tape was used.
Incidentally, after the receptor sheet 15 is welded on the
elastomer member 10 and then the urging jig 45 is removed, the
deformation of the elastomer member 10 is eliminated, so that the
receptor sheet 15 is spaced from the surface 49.
[0089] Further, as a near infrared ray irradiation device, a device
("FD200" (wavelength: 960 nm), mfd. by FINE DEVICE Co., Ltd.) was
used. A longitudinal scanning speed of the near infrared ray
irradiation device was 50 mm/sec, an output was 20 W, and a spot
diameter on the elastomer member surface was 1.5 mm. Further, an
energy density at the surface of the elastomer member 10 was 0.22
J/mm.sup.2. Further, as the elastomer member 10, a member prepared
by incorporating 0.5 to 12.0 wt. parts of carbon black into 100 wt.
parts of the styrene-based elastomer resin material was used.
[0090] The above-described bonding method between the receptor
sheet 15 and the elastomer member 10 formed on the cleaning
container 24 by molding can also be applied to welding between the
blow off preventing sheet 16 and the elastomer member 11 formed on
the developing container 71 by molding. Similarly, the bonding
method is also applicable to bonding between the charging roller
cleaner 17 and the elastomer member 12 formed on the cleaning
container 24 by molding. Further, the bonding method is also
applicable to welding between the scattering preventing sheet 18
and the elastomer member 13 formed on the developing container 71
by molding. Further, in this embodiment, the receptor sheet 15
having the light transmittance of 85% or less may also be weldable.
Further, as a method other than the welding (bonding) method in
this embodiment, the elastomer member 10 and the receptor sheet 15
may also be welded by heat seal or the like. Incidentally, by the
heat seal or the like, heat cannot be applied to only a bonded
interface between the receptor sheet 15 and the elastomer member 10
but is conducted (applied) from an upper surface of the receptor
sheet 15. Therefore, there is also a need to take a heat conduction
time and melting of the receptor sheet 15 into consideration.
[0091] In the case of the conventional method using the double-side
tape as the adhesive member, after left-standing in the high
temperature environment, deviation is generated at the bonded
interface between the double-side tape and each of the sheet
members such as the receptor sheet 15, so that the initial tension
of the sheet member is attenuated. In this embodiment, the sheet
member and each of the elastomer members 10 to 13 are bonded by the
welding. Further, by making an elastic modulus of the elastomer
member smaller than that of the frame such as the cleaning
container 24 or the developing container 71, an amount of permanent
deformation of the elastomer member after being left standing in
the high temperature environment can be made small. Further, after
the left-standing in the high temperature environment, deviations
at a bonded interface between the sheet member and the elastomer
member and at a bonded interface between the frame and the
elastomer member are not generated and therefore the initial
tension of the sheet member can be maintained.
[0092] The elastomer member formed on the frame by molding in this
embodiment specifically has a shape as shown in FIG. 24 such that
dimensions thereof are h=0.6 to 0.8 mm, i=0.1 to 0.3 mm, j=1.0 mm,
k=0.3 mm and r=1.6 mm. Here, h is a free length of the elastomer
member during molding, i is an elastomer member melting margin, j
is an elastomer member molding width (upper side), k is an entering
amount of the elastomer member entering the container, and r is an
elastomer member molding width (bottom side). In such a dimensional
constitution, a section modulus is about 0.25. Further, the
material for forming the frame is HIPS (high-impact polystyrene)
and its linear expansion coefficient is 0.000087 (1/.degree. C.),
and an elastic modulus of the material is 2.38 GPa. The material
for the sheet member is polyester and is 38 .mu.m in thickness,
0.000015 (1/.degree. C.) in linear expansion coefficient and 4.5
GPa in elastic modulus. That is, a degree of temperature change of
the frame is about 5.8 times that of the sheet member. Therefore,
when a left-standing environment is changed from normal temperature
(e.g., 23.degree. C.) to 50.degree. C., a load corresponding to a
difference in elongation between the frame and the sheet member is
applied to the elastomer member sandwiched between the frame and
the sheet member. This load is a difference in displacement between
the frame and the sheet member in the 50.degree. C. environment. In
the case where the displacement under the 50.degree. C. environment
is calculated, the elongation amount of the frame (having a full
length of 220 mm equal to that of the sheet member) is 0.52 mm and
the elongation amount of the sheet member is 0.09 mm, so that the
elongation difference .DELTA. is 0.43 mm.
[0093] As described above, by making the elastic modulus of the
elastomer member being a range, of 2.5 MPa or more and 10 MPa or
less, which is smaller than the elastic modulus of the sheet
member, it is possible to decrease the amount of permanent
deformation of the elastomer member, due to the load under the
50.degree. C. environment, at the time when the ambient temperature
is restored to normal temperature. Further, each of the bonded
interface between the frame and the elastomer member and the bonded
interface between the sheet member and the elastomer member is
formed by molding and welding and therefore no deviation is
generated, so that the initial tension of the sheet member can be
maintained. As a result, it becomes possible to prevent the waving
of the sheet member.
[0094] As described above, according to Embodiment 1, the elastomer
member is directly formed on the frame by molding and therefore it
is possible to effect assembling with a higher degree of accuracy
than that in the case of the double-side tape. Further, the
deviation of the bonded interface, generated in the case of using
the double-side tape, between the frame and the double-side tape
after being left standing in the high temperature environment can
be eliminated. Further, by bonding the sheet member and the
elastomer member to each other by welding, it is possible to
eliminate the deviation of the bonded interface, generated in the
case of using the double-side tape as the adhesive member, between
the sheet member and the double-side tape after being left standing
in the high temperature environment. Further, by making the elastic
modulus of the elastomer member smaller than the elastic modulus of
the frame or the sheet member, the amount of permanent deformation
of the elastomer member after being left standing in the high
temperature environment can be made small. Further, there are no
deviations of the bonded interface between the frame and the
elastomer member and the bonded interface between the sheet member
and the elastomer member, and therefore the initial tension of the
sheet member can be maintained, so that the waving of the sheet
member can be prevented.
Embodiment 2
[0095] Next, Embodiment 2 of the present invention will be
described. Members or portions common to Embodiments 1 and 2 will
be omitted from description.
[0096] The elastomer member formed on the frame by molding in this
embodiment specifically has a shape as shown in FIG. 24 such that
dimensions thereof are h=0.6 to 0.8 mm, i=0.1 to 0.3 mm, j=1.0 mm,
k=0.3 mm, r=1.6 mm, and (p1, p2)=0.75 to 1.05 mm. Here, h is a free
length of the elastomer member during molding, i is an elastomer
member melting margin, j is an elastomer member molding width
(upper side), k is an entering amount of the elastomer member
entering the container, and r is an elastomer member molding width
(bottom side).
[0097] The above-described various structural examples of the
molded shape of the elastomer member 10 on the cleaning container
24 are also applicable to the molded shapes of the elastomer
members 11 and 13 on the developing container 71 and the molded
shape of the elastomer member 12 on the cleaning container 24.
(Sheet Welding)
[0098] With reference to FIGS. 29 to 34, a sheet member welding
process in this embodiment of the present invention will be
described by taking the case of using laser welding, as an example.
Parts (a) and (b) of FIG. 29 are schematic illustrations of the
cleaning container on which the receptor sheet 15 is mounted, in
which (a) of FIG. 29 shows a state in which waving of the receptor
sheet 15 is not generated, and (b) of FIG. 29 shows a state in
which waving of a widthwise edge 15a of the receptor sheet 15 is
generated. Parts (a) and (b) of FIG. 30 are schematic views for
illustrating a method of imparting tension to an upper edge of the
receptor sheet, in which (a) of FIG. 30 shows a state in which the
receptor sheet 15 is placed on the sheet member mounting surface
24d of the cleaning container 24 under tension. The tension is
generated by holding the receptor sheet 15 at two longitudinal end
portions 15c and 15d in an upper edge 15a side and then by pulling
the receptor sheet 15 in arrow L1 and L2 directions. Further, (b)
of FIG. 30 shows a state in which the tension is imparted to the
upper edge 15a of the receptor sheet 15. FIG. 31 is a schematic
view for illustrating a state in which the elastomer member 10
formed on the cleaning container 24 by molding is melted to weld
another (lower) edge 15b of the receptor sheet 15. FIG. 32 is a
schematic sectional view showing the state of FIG. 31. FIG. 33 is a
partially enlarged view of portion D shown in FIG. 32. FIG. 34 is a
schematic view for illustrating the cleaning container 24 on which
the receptor sheet 15 is welded on the elastomer member 10.
[0099] In this embodiment, the receptor sheet 15 formed of
polyester with a thickness of 38 .mu.m and a light transmittance of
85% (near infrared ray of 960 nm) was used. First, as shown in (a)
of FIG. 29, when the receptor sheet 15 is mounted on the cleaning
container 24, waving x as shown in (b) of FIG. 29, can occur at the
edge (contact portion with the image bearing member 21) 15a of the
receptor sheet 15 due to creases of the receptor sheet 15 itself,
an environmental fluctuation, and the like. For this reason, when
the receptor sheet 15 is mounted, as shown in (a) of FIG. 30, the
two longitudinal end portions 15c and 15d of the receptor sheet 15
in the upper edge 15a side are pulled in the arrow L1 and L2
directions by an unshown sheet-pulling jig. In this state, by
mounting the receptor sheet 15 on the sheet member mounting surface
24d of the cleaning container 24, an initial tension amount n is
provided to the edge 15a of the receptor sheet 15 as shown in (b)
of FIG. 30, so that waving is prevented. In this embodiment, the
initial tension amount n of about 0.3 mm is provided.
[0100] As shown in FIGS. 31 to 33 in a state in which the tension
is applied to the edge 15a of the receptor sheet 15 by using the
unshown pulling jig, the receptor sheet 15 is superposed on the
sheet member mounting surface 24d in its lower edge side so as to
be contacted to the sheet member mounting surface 24d. Further, the
receptor sheet 15 is press-contacted to a sheet regulating surface
(regulating portion) 49 for regulating a sheet position by using an
urging jig 45, which is transparent to near infrared ray, from
above the receptor sheet 15. As a result, the receptor sheet 15 is
temporarily positioned so that a position of the receptor sheet 15
relative to the cleaning container 24 is not shifted (deviated)
during bonding of the receptor sheet 15.
[0101] Thereafter, laser light e of near infrared ray is emitted
from a laser irradiation head 60, via the receptor sheet 15, toward
the sheet member mounting surface 24d of the elastomer member 10
formed on the cleaning container 24 by molding. The elastomer
member 10 contains carbon black so as to absorb near infrared ray.
For this reason, the emitted laser light e passes through the
urging jig 45 and the receptor sheet 15 which are transparent to
near infrared ray, and is absorbed by the sheet member mounting
surface 24d of the elastomer member 10 formed on the cleaning
container 24 by molding. The laser light absorbed by the sheet
member mounting surface 24d is conversed into heat and thus the
sheet member mounting surface 24d generates heat, so that the
elastomer member 10 is melted at its edge portion by the heat and
thus can be welded with (bonded to) the edge portion 15b of the
receptor sheet 15 contacting the sheet member mounting surface 24d.
After the (heat) welding, the urging jig 45 is disconnected, so
that the elastomer member 10 is released from the compressed state
and is then elastically restored in the urging direction, thus
being increased in height. As a result, the contact position
between the elastomer member 10 and the receptor sheet 15 becomes
higher than the height of the sheet regulating surface 49.
[0102] Here, the laser light e emitted from the irradiation head 60
was focused to a circular spot of 1.5 mm in diameter when it
reaches the sheet member mounting surface 24d. That is a spot
diameter of the laser light is 1.5 mm. Further, by making a molding
width of the elastomer member smaller than 1.5 mm, it becomes
possible to uniformly melt the sheet member mounting surface 24d of
the elastomer member 10. Therefore, in this embodiment, a melting
width el of the elastomer member 10 is about 1.0 mm. Further, the
receptor sheet 15 is irradiated with the laser light continuously
from its end portion to its another end portion. As a result, a
welded surface g1 continuously extending in the longitudinal
direction as shown in FIG. 34 can be obtained.
[0103] Further, as the urging jig 45, a member having a rigidity
such that it can press an entire contact surface between the
receptor sheet 15 and the sheet member mounting surface 24d of the
elastomer member 10 formed on the cleaning container 24 by molding
may preferably be used. Specifically, acrylic resin, glass and the
like may preferably be used.
[0104] Further, the cleaning container 24 on which the elastomer
member 10 having the sheet member mounting surface 24d is formed by
molding is formed of the resin material, so that when the receptor
sheet 15 is mounted, the sheet member mounting surface 24d is
curved to cause some unevenness or deformation in some cases.
Further, in some cases, the position of the receptor sheet 15
relative to the cleaning container 24 is shifted. Therefore, in
this embodiment, the urging jig 45 was provided with an elastic
urging member 47. By the urging member 47, the receptor sheet 15 is
elastically urged toward the cleaning container 24 to be
temporarily positioned, so that an adhesive property between the
receptor sheet 15 and the sheet member mounting surface 24d can be
improved. Further, positional deviation of the receptor sheet 15
can be prevented. Specifically, as the urging jig 45, a member
including an acrylic member 46 as a rigid member and a 5 mm-thick
silicone rubber member (urging member) 47 as an elastic member
which are bonded with a transparent double-side tape was used.
[0105] Further, as the elastomer member 10, a member prepared by
incorporating 0.5 to 12.0 wt. parts of carbon black into 100 wt.
parts of the styrene-based elastomer resin material was used.
[0106] The above-described bonding method between the receptor
sheet 15 and the elastomer member 10 formed on the cleaning
container 24 by molding can also be applied to welding between the
blow off preventing sheet 16 and the elastomer member 11 formed on
the developing container 71 by molding. Similarly, the bonding
method is also applicable to bonding between the charging roller
cleaner 17 and the elastomer member 12 formed on the cleaning
container 24 by molding. Further, the bonding method is also
applicable to welding between the scattering preventing sheet 18
and the elastomer member 13 formed on the developing container 71
by molding. Further, in this embodiment, the receptor sheet 15
having the light transmittance of 85% or less may also be weldable.
Further, as a method other than the welding (bonding) method in
this embodiment, the elastomer member 10 and the receptor sheet 15
may also be welded by heat seal or the like. Incidentally, by the
heat seal or the like, heat cannot be applied to only a bonded
interface between the receptor sheet 15 and the elastomer member 10
but is conducted (applied) from an upper surface of the receptor
sheet 15. Therefore, there is also a need to take a heat conduction
time and melting of the receptor sheet 15 into consideration.
[0107] With reference to FIGS. 35 and 36, a cross-sectional shape
after the sheet member welding in this embodiment of the present
invention will be described. FIG. 35 is a schematic sectional view
of a welding portion when the receptor sheet 15 is mounted on the
cleaning container 24. FIG. 36 is a schematic sectional view
showing a state in which the receptor sheet 15 is contacted to the
regulating portion 49a of the sheet regulating surface 49.
[0108] First, as shown in FIG. 35, welding burrs z are generated on
the elastomer member 10, so that the receptor sheet 15 is partly
provided with curvature (arcuate shape), thus being placed in a
state of welding on the elastomer member 10 in some cases. In this
state, the receptor sheet 15 is falls in its edge 15a side in an
arrow a direction shown in FIG. 36, so that it is difficult to
ensure accuracy of the receptor sheet edge 15a. Therefore, as shown
in FIG. 36, the receptor sheet 15 is contacted to the sheet
regulating surface 49 with respect to the longitudinal direction,
so that the falling in the arrow a direction of the receptor sheet
15 with respect to the widthwise direction is prevented and thus it
becomes possible to stabilize the position of the edge 15a of the
receptor sheet 15. At this time, in order to bring the receptor
sheet 15 into contact with the sheet regulating surface 49, there
is a need to provide a spacing p1 between the elastomer member 10
and the cleaning container 24 to same extent. This is because in
the case where the spacing p1 is narrow and a welding surface
height y is large, the receptor sheet 15 is not contacted to the
sheet regulating surface 49 and falls in the arrow a direction.
[0109] In this embodiment, the welding surface height y was 0.05 to
0.15 mm and therefore in order to bring the receptor sheet 15 into
contact with the regulating portion 49a of the sheet regulating
surface 49, the spacing p1 was 0.75 to 1.05 mm. At this time, an
angle b formed between the receptor sheet 15 and the sheet
regulating surface 49 was 1 to 2 degrees.
[0110] Incidentally, the above-described sheet regulating structure
is not limited to that described above so long as the sheet
regulating surface 49 is contactable to the receptor sheet 15 so
that the position of the edge 15a of the receptor sheet 15 is
regulated at a position where the edge 15a contacts the image
bearing member 21. Further, the receptor sheet 15 may preferably be
contacted to the sheet position regulating surface 49 over an
entire longitudinal region but may also be partly contacted to the
sheet position regulating portion 49.
[0111] In the above, the shape when the receptor sheet 15 is welded
on the elastomer member 10 formed on the cleaning container 24 by
molding was described. However, the shape in Embodiment 2 is also
applicable to the shape when the blowoff preventing sheet 16 is
welded on the elastomer member 11 formed on the developing
container 71 by molding. Further, the shape is also applicable to
the shape when the charging roller cleaner 17 is welded on the
elastomer member 12 formed on the cleaning container 24 by molding.
In addition, the shape is also applicable to the shape when the
scattering preventing sheet 18 is welded on the elastomer member 13
formed on the developing container 71 by molding.
[0112] As described above, according to Embodiment 2, the elastomer
member is directly formed on the frame by molding, so that
assembling of the elastomer member with high accuracy can be
effected. Further, according to the sheet regulating structure
described above, irrespective of the welding state (the shape of
the welding portion after the welding) between the elastomer member
and the sheet member (thin plate member), tilting of the sheet
member in the widthwise direction can be prevented and thus it is
possible to stabilize the edge position of the sheet member.
Embodiment 3
[0113] Next, Embodiment 3 of the present invention will be
described. Members or portions common to Embodiments 1 and 3 will
be omitted from description.
[0114] The elastomer member formed on the frame by molding in this
embodiment specifically has a shape as shown in FIG. 24 such that
dimensions thereof are h=0.6 to 0.8 mm, i=0.1 to 0.3 mm, j=1.0 mm,
k=0.3 mm and r=1.6 mm. Here, h is a height of the elastomer member
during molding, i is an elastomer member melting margin for
permitting melting of the elastomer resin material by laser molding
during sheet member bonding, j is an elastomer member molding width
(upper side), k is an entering amount of the elastomer member
entering the container, and r is an elastomer member molding width
(bottom side). In such a dimensional constitution, a section
modulus is about 0.25.
[0115] As shown in (a) of FIG. 37, a cross-sectional shape
(excluding a portion where the elastomer member 10 enters the
cleaning container 24) perpendicular to (crossing) the longitudinal
direction in a region in which the elastomer member 10 is to be
compressed (pressed) between the cleaning container 24 and the
receptor sheet 15 is made trapezoidal. As a result, buckling of the
elastomer member during compression can be prevented. Parts (a),
(b), (a-1) and (b-1) of FIG. 37 are schematic sectional views for
illustrating a molded shape effect of the elastomer member in this
embodiment in which (a) shows a state before compression in the
case where the cross-sectional shape is trapezoidal, (b) shows a
state during compression in the case where the cross-sectional
shape is trapezoidal (a-1) shows a state before compression in the
case where the cross-sectional shape is rectangular, and (b-1)
shows a state during compression in the case where the
cross-sectional shape in rectangular. That is, as shown in (a-1)
and (b-1), in the case where the cross-sectional shape of the
elastomer member 10 is rectangular, buckling is generated, so that
deformation such that the elastomer member 10 acts violently with
respect to a direction (q2 direction) perpendicular to a
compression direction (q1 direction) when the elastomer member 10
is compressed and thus an attitude of the elastomer member 10 is
not stabilized. In such a state, welding of the receptor sheet 15
becomes insufficient and thus deviation is generated at the welding
surface, so that tilting or the like of the receptor sheet 15 after
the welding is generated. On the other hand, as shown in (a) and
(b) of FIG. 37, the cross-sectional shape is made trapezoidal such
that its width is gradually increased with respect to the
compression direction, whereby shape stability during the
compression can be enhanced to suppress the generation of
buckling.
[0116] The cross-sectional shape of the elastomer member is not
limited to the trapezoidal shape so long as the shape has high
shape stability during the compression. That is, the
cross-sectional shape of the elastomer member in a region where the
elastomer member is compressed between the thin plate member and
the frame to cause deformation may only be required to be
increased, in width with respect to the direction perpendicular to
the compression direction, from the thin plate member size to the
frame side. Parts (a) to (d) of FIG. 38 show modified examples of
the above-described cross-sectional shape of the elastomer member.
Next, the material for forming the frame is HIPS (high-impact
polystyrene) and its linear expansion coefficient is 0.000087
(1/.degree. C.), and an elastic modulus of the material is 2.38
GPa. The material for the sheet member is polyester and is 38 .mu.m
in thickness, 0.000015 (1/.degree. C.) in linear expansion
coefficient and 4.5 GPa in elastic modulus. That is, a degree of
temperature change of the frame is about 5.8 times that of the
sheet member. Therefore, when a left-standing environment is
changed from normal temperature (e.g., 23.degree. C.) to 50.degree.
C., a load corresponding to a difference in elongation between the
frame and the sheet member is applied to the elastomer member
sandwiched between the frame and the sheet member. This load is a
difference in displacement between the frame and the sheet member
in the 50.degree. C. environment. In the case where the
displacement under the 50.degree. C. environment is calculated, the
elongation amount of the frame (having a full length of 220 mm
equal to that of the sheet member) is 0.52 mm and the elongation
amount of the sheet member is 0.09 mm, so that the elongation
difference A is 0.43 mm.
[0117] As described above, by making the elastic modulus of the
elastomer member being a range, of 2.5 MPa or more and 10 MPa or
less, which is smaller than the elastic modulus of the sheet
member, it is possible to decrease the amount of permanent
deformation of the elastomer member, due to the load under the
50.degree. C. environment, at the time when the ambient temperature
is restored to normal temperature. Further, each of the bonded
interface between the frame and the elastomer member and the bonded
interface between the sheet member and the elastomer member is
formed by molding and welding and therefore no deviation is
generated, so that the initial tension of the sheet member can be
maintained. As a result, it becomes possible to prevent the waving
of the sheet member.
[0118] As described above, according to Embodiment 1, the elastomer
member is directly formed on the frame by molding and therefore it
is possible to effect assembling with a higher degree of accuracy
than that in the case of the double-side tape. Further, the
deviation of the bonded interface, generated in the case of using
the double-side tape, between the frame and the double-side tape
after being left standing in the high temperature environment can
be eliminated. Further, by bonding the sheet member and the
elastomer member to each other by welding, it is possible to
eliminate the deviation of the bonded interface, generated in the
case of using the double-side tape as the adhesive member, between
the sheet member and the double-side tape after being left standing
in the high temperature environment. Further, by making the elastic
modulus of the elastomer member smaller than the elastic modulus of
the frame or the sheet member, the amount of permanent deformation
of the elastomer member after being left standing in the high
temperature environment can be made small. Further, there are no
deviations of the bonded interface between the frame and the
elastomer member and the bonded interface between the sheet member
and the elastomer member, and therefore the initial tension of the
sheet member can be maintained, so that the waving of the sheet
member can be prevented.
[0119] While the invention has been described with reference to the
structures disclosed herein, it is not confined to the details set
forth and this application is intended to cover such modifications
or changes as may come within the purpose of the improvements or
the scope of the following claims.
[0120] This application claims priority from Japanese Patent
Applications Nos. 245731/2011 filed Nov. 9, 2011; 275772/2011 filed
Dec. 16, 2011; and 275773/2011 filed Dec. 16, 2011, which are
hereby incorporated by reference.
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